Thanks for all the replys. I will have to pattern it when I get a day or two off. The three inch 00 shells are just what I had laying around. I'm kind of fond of 2-3/4" myself. I just didn't want to make a mistake and overchoke it possibly ruining the choke/barrel, if that's even possible.
It's a handy package even though it doesn't swing as nice as the longer barrel. Would it be viable as a field gun just to fill the cook pot or is the 20" best suited for ranch duty?